Automatically controlled calender



Jan. 27, 1953 J. B. COLLINS 2,626,423

AUTOMATICALLY CONTROLLED CALENDER Filed June 11, 1948 2 SHEETS-SHEET 1 Inventor (JACK B. COLL/N5 Attorneys Jan. 27, 1953 J. B. COLLINS AUTOMATICALLY CONTROLLED CALENDER 2 SHEETS-SHEET 2 Filed Ju ne 11, 1948 FIG. 2;

FIG. 3.

' Inventor (/AC/f 8.6'0LL/M5 B Attorneys Patented Jan. 27, 1953 AUTOMATICALLY CONTROLLED CALENDER Jack B. Collins, Isleworth, England, assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio Application June 11, 1948, Serial No. 32,402 In Great Britain June 17, 1947 2 Claims.

The present invention relates to calenders and is more particularly concerned with calenders for coating an insulating material such as rubber or an adhesive on to a backing made of any suitable material, such as textile fabric, paper, metal foil, cellulose or synthetic resin.

The chief object of the present invention is to provide an improved calender having means for controlling the operation of the calender in accordance with the continuity of the film or layer of coating material to be applied to the backing material.

According to the present invention the coating material as it passes over the surface of one of the bowls of the calender for application to the backin material is adapted to control or influence an electric circuit controlling the operation of the calender.

In order that the invention may be more clearly understood the same will now be more particularly described with reference to the accompanying drawings, in which:

Fig. 1 shows in schematic outline the device as fitted to the centre bowl of a. three-bowl calender.

Fig. 2 shows a detail view of one of the contact figures and its actuating weight.

3 shows the electrical circuit for controlling the calendering operation.

In Fig. 1 the three bowls of the calender, upper, middle and lower, are indicated by the numerals l, 2, 3, respectively, and the circuit controlling means is shown as being applied to the middle bowl 2.

The bowls may be driven and geared together in known manner, the means not being shown in the drawings. Stub shafts 4 are shown for driving the bowls, the shafts being supported in bearings (not shown) in normal manner.

For simplicity the circuit controlling means is shown as being applied to one end only of the middle bowl, the other ends of all of the bowls being shown as broken oil. It is to be understood, however, that the control means extends the entire length of the bowl of the calender.

In one contemplated constructional form of the present invention as applied to a calender for shim coating rubber on to textile fabric for use in the manufacture of pneumatic tyres, the film or layer of rubber produced at the nip of the top and middle bowls and being conveyed by the middle bowl 2 of a three-bowl calender to a strip of textile fabric passing between the middle and lowest bowls of the calender, is utilized to maintain one or more contact arms 5 out of contact with the surface of the bowl and so prevent the establishment of an electric circuit which controls operation of the calender. A series of contact arms 5 extending longitudinally of the bowl and indepedently operable are contemplated, each arm being urged resilientlyeither due to its own inherent resilience or by spring means into contact with the bowl,

In preferred form, as shown in Fig. 2, the contact members 5 consist of metallic sprin blades bearing upon the surface of the bowl 2 or upon a film or layer of coatin material thereon, as the case may be, at one end of the blade whilst the other end is secured to a blade securing means consisting, in the preferred example, of a mild steel strip 6 bent intermediate of its length to form a U-shaped member, having the arms of the U disposed in slightly diverging relation. Each U-member, with its contact member, is secured at the bend in the U, upon an electrical conducting tube 1, a number of which are supported upon an internal concentric rod 8, each end of which is supported in insulating blocks (not shown).

One U-member 6 is placed over each tubular element 7, as shown (Figs. 1 and 2), so that the U-portion partially encircles the tubular element. The other arm of the U-member, i. e, the one not connected to the contact member, carries a weight 9 which serves to maintain the end of the member 5 in contact with the bowl 2 or layer of mate rial thereon, the U-member pivoting about the conductor =8 in order to do this. Sufiicient contact members 5 are provided to ensure that a large area of the bowl surface is engaged thereby so that at the first sign of the film becomin discontinuous the calender will be stopped.

The conducting rod 8 is supported at intermediate parts of its length by brackets, or the like, i0 secured to the frame of the machine through the intervention of electrical insulating means, as shown.

In order that the device may be put out of action when desired a contact finger lifting bar H is provided, this passing between the arms of all of the U-members. This lifting bar is swingably supported in the ends of a number of levers l2, pivotably supported at I3 upon a supporting rod M which may be secured, through the intervention of electrical insulating means, to the frame of the machine at the same, or substantially the same points as the brackets to are secured.

As shown, the levers l2 are extended beyond their pivotal points 13 to support an additional rod 15 which may be grasped by the hand of 3 an operator at any part of its length and depressed so as to raise the lifting bar II which then engages with all of the U-members 6 to lift the contacts 5 from the bowl.

The electrical circuit may be so devised and connected as to control the calendering operation in any desired manner, for example by controlling the rotation of the calender bowls or the feed of the rubber.

In this form of the invention if the film or layer of rubber becomes discontinuous or patchy, one or more of the contact arms 5 makes contact with the bowl 2 and establishes the electrical circuit to control the calender.

In a particular contemplated arrangement (as shown in Fig. 3) for this purpose, 230.volt 50 cycle alternating current is stepped down to 15 volts by means of a transformer IE. One terminal of the 15 volt output of this transformer is connected to the contact arms 5 extending along the calender bowl 2, and the other lead to one terminal of the primary of a step-up transformer ll (15 volts to 110 volts). The other terminal of the step-up transformer H is connected to the frame of the calender. Thus the primary of this transformer is energized at 15 volts from the secondary of the firstvtransformer via the contact arms and calender bowl. The output of this transformer (at 110 volts) operates a relay l8 and a signal lamp [9, the relay in turn operating the circuit 18a for switching ofi and stopping the calender motor.

A press button 29 is provided in the 230 volt circuit, in order to isolate the system. This is necessary after the device has operated. It would be impossible to restart the calender without first de-energizing the system. The action of depressing the button 20 opens the 230 volt circuit on the first transformer, and it is held depressed until the middle bowl is again completely covered with rubber.

It will be appreciated that ,many, different forms of contact members 5, 6 and the means for lifting them from the bowl surface could be devised and it is not, therefore, desired to restrict the application to any particular modification of these parts.

In another contemplated arrangement instead of using the coating material to maintain the contact arms out of contact with the bowl, the

coating material may be used as the dielectric of a condenser, one plate of which is constituted by the surface of the calender bowl and the other plate of which is constituted by an arcuate plate disposed parallel to a part of the said surface. This condenser is connected in a suitable circuit and it will be seen thatif the coating material becomes discontinuous at any place the 4 capacity of the condenser is varied to influence the circuit in which it is connected and thus initiate the desired control of the calender.

The present invention may be applied to any calender and for coating any insulating material on to a backing,.the only requirement being that the coating material is an insulating material.

I claim:

1. In a calender, an electrical circuit for de tecting discontinuities in a calendered layer of relatively soft, gummy, insulating material as it passes through the calender, said circuit comprising oneJof the rolls of said calender and a plurality of independently movable contact members pivotally mounted about an axis adjacent to said roll, each member having a fiat blade portion extending from said axis in the direction of rotation of said roll and having wiping contact with said layer over a substantial area, means to urgesaid members in the direction of said one roll, said members being adapted to contact the said one roll whenever said coating becomes discontinuous to energize said circuit, and means adapted to control the operation of said calender upon the energization of said circuit.

2. In a calender, an electrical circuit for detecting discontinuities in a calendered layer of relatively soft, gummy, insulating material as it passes through the calender, said circuit comprisingone of the rolls'of said calender and a plurality of independently movable contact members mounted adjacent said roll, each member having a flat portion extending in the direction of rotation of said. roll and having wiping contact with said, layer over a substantial area, means to urge said members in the direction of said one roll, said members being adapted to contact the said one roll when said coating becomes discontinuous to energize said circuit, and means adapted'to control the operation of said calender upon the energization of said circuit.

JACK B. COLLINS.

REFERENCES CITED The following'references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,228,173 Beregh May 29, 1917 1,878,109 Clark Sept. 20, 1932 2,124,410 Cockrell July 19, 1938 2,141,052 Stephano Dec. 20, 1938 2,200,293 Pelosi May 14, 1940 2,270,732 Jones Jan. 20, 19.42 2,424,856 Schnuck July 29, 1947 2,438,787 Nicholas Mar. 30, 1948 

